Spice and Wolf The Sacred Blacksmith Tears to TiaraZero no TsukaimaRomeo X Juliet

Spice and Wolf is the most historically accurate (Besides the main character) but the world they are in is very good for that. Zaero no Tsukaima is the most fantasy with everyone having magic powers and flying dragons, things like that. Blacksmith and Tears, the main characters are very fantasy and the world is more medieval

Record of Lodoss War is a classic that fits pretty well.Twelve Kingdoms is set in pretty much feudal Japan, so not the western Medieval, but similar.Slayers is set in a swords-and-sorcery sort of Medieval.